Actress Keira Knightley has opened the 64th Venice Film Festival with the premiere of her latest film Atonement.

The film, based on Ian McEwan's wartime novel, is in official competition for the Golden Lion award for best film.

Knightley, 22, was joined on the red carpet at Venice's Palazzo del Cinema by co-stars James McAvoy and Vanessa Redgrave, and director Joe Wright.

Actors Jude Law and Sir Michael Caine are also at the festival for the premiere of their new film Sleuth.

Oscar chances

A total of 22 films will vie for the prestigious prize, which is often seen as a strong indicator of Oscar success.

Dame Helen Mirren won the best actress prize at the festival last year, and went on to take the Oscar for her role in The Queen.

But Knightley, who wore a pale pink strapless gown by Chanel at the premiere, played down her Oscar chances.

"As far as awards go, that's neither here nor there," she said. "Atonement was a complete gift. I read the script and I cried. Any script that makes you cry is worth pursuing."

Sir Michael and Law are in Venice for the premiere of Sleuth

In British thriller Sleuth, Law, 37, is playing the role made famous by Sir Michael in the original 1972 film.

Sir Michael, 74, is also appearing in the film, in the part originally played by Sir Laurence Olivier.

At a press conference to promote the latest version, Law admitted that the last time he took on a role made famous by Sir Michael - Alfie - it did not go according to plan.

The 2004 update is regularly included in lists of the worst-ever movie remakes.

"The modern version of Alfie to me was a challenge because I hadn't played a character like that before. I don't know that I did it particularly well," said Law, with Sir Michael sitting beside him.

"Michael is many, many, many actors' heroes and he is certainly an acting hero of mine. When I was approached originally to work on the new version of Alfie, it seemed like a brilliant idea because the original was so successful.

"From my point of view, it didn't quite turn out the way I wanted it to."

Deadly game

Law plays Milo Trindle, an out-of-work actor who has stolen the wife of multi-millionaire crime writer Andrew Wyke.

Wyke invites the younger man to his country home and draws him into a deadly game of wits.

The remake is directed by Branagh, from a script by Harold Pinter.

Taiwanese director Ang Lee also arrived in Venice for the premiere of his Chinese-language spy thriller Lust, Caution (Se, Jie).

The film follows a Chinese woman in Japanese-occupied Shanghai during World War II, who finds herself in the centre of a plot to seduce and kill a married enemy collaborator.